Untitled

<?php
// Include config file
if(isset($_POST['register'])){

	require_once 'config.php';

	// Define variables and initialize with empty values
	$username = $password = $confirm_password = "";
	$username_err = $password_err = $confirm_password_err = "";

	// Processing form data when form is submitted
	if($_SERVER["REQUEST_METHOD"] == "POST"){

		// Validate username
		if(empty(trim($_POST["username"]))){
			$username_err = "Please enter a username.";
		} else{
			 // Prepare a select statement
			$sql = "SELECT id FROM users WHERE username = ?";

			if($stmt = mysqli_prepare($link, $sql)){
				// Bind variables to the prepared statement as parameters
				mysqli_stmt_bind_param($stmt, "s", $param_username);

				// Set parameters
				$param_username = trim($_POST["username"]);

				// Attempt to execute the prepared statement
				if(mysqli_stmt_execute($stmt)){
					/* store result */
					mysqli_stmt_store_result($stmt);

					if(mysqli_stmt_num_rows($stmt) == 1){
						$username_err = "This username is already taken.";
					} else{
						$username = trim($_POST["username"]);
					}
				} else{
					echo "Oops! Something went wrong. Please try again later.";
				}
			}

			// Close statement
			mysqli_stmt_close($stmt);
		}

		// Validate password
		$uppercase = preg_match('@[A-Z]@', $_POST['password']);
		$lowercase = preg_match('@[a-z]@', $_POST['password']);
		$number    = preg_match('@[0-9]@', $_POST['password']);
		if(empty(trim($_POST['password']))){
			$password_err = "Please enter a password.";
		} elseif(!$uppercase || !$lowercase || !$number || strlen(trim($_POST['password'])) < 8){
			$password_err = "Password must have atleast 8 characters, a uppercase letter and lowercase letter.";
		} else{
			$password = trim($_POST['password']);
		}

		// Validate confirm password
		if(empty(trim($_POST["confirm_password"]))){
			$confirm_password_err = 'Please confirm password.';
		} else{
			$confirm_password = trim($_POST['confirm_password']);
			if($password != $confirm_password){
				$confirm_password_err = 'Password did not match.';
			}
		}

		// Check input errors before inserting in database
		if(empty($username_err) && empty($password_err) && empty($confirm_password_err)){

			// Prepare an insert statement
			$sql = "INSERT INTO users (username, password) VALUES (?, ?)";

			if($stmt = mysqli_prepare($link, $sql)){
				// Bind variables to the prepared statement as parameters
				mysqli_stmt_bind_param($stmt, "ss", $param_username, $param_password);

				// Set parameters
				$param_username = $username;
				$param_password = password_hash($password, PASSWORD_DEFAULT); // Creates a password hash

				// Attempt to execute the prepared statement
				if(mysqli_stmt_execute($stmt)){
					// Redirect to login page
					header("location: login.php");
				} else{
					echo "Something went wrong. Please try again later.";
				}
			}

			// Close statement
			mysqli_stmt_close($stmt);
		}

		// Close connection
		mysqli_close($link);
	}
}
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Sign Up</title>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
    <style type="text/css">
        body{ font: 14px sans-serif; }
        .wrapper{ width: 350px; padding: 20px; }
    </style>
</head>
<body>
    <div class="wrapper">
        <h2>Sign Up</h2>
        <p>Please fill this form to create an account.</p>
        <form name = "register" id = "register" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
            <div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
                <label>Username:<sup>*</sup></label>
                <input type="text" name="username"class="form-control" value="<?php echo $username; ?>">
                <span class="help-block"><?php echo $username_err; ?></span>
            </div>
            <div class="form-group <?php echo (!empty($password_err)) ? 'has-error' : ''; ?>">
                <label>Password:<sup>*</sup></label>
                <input type="password" name="password" class="form-control" value="<?php echo $password; ?>">
                <span class="help-block"><?php echo $password_err; ?></span>
            </div>
            <div class="form-group <?php echo (!empty($confirm_password_err)) ? 'has-error' : ''; ?>">
                <label>Confirm Password:<sup>*</sup></label>
                <input type="password" name="confirm_password" class="form-control" value="<?php echo $confirm_password; ?>">
                <span class="help-block"><?php echo $confirm_password_err; ?></span>
            </div>
            <div class="form-group">
                <input type="submit" name="register" class="btn btn-primary" value="Submit">
                <input type="reset" class="btn btn-default" value="Reset">
            </div>
            <p><a href="login.php">Login here</a>.</p>
        </form>
		<form action="createTable.php" method="get">
			    <input type="submit" class="btn btn-primary" value="Create Table">
				</form>
    </div>
</body>
</html>